Stem cells are types of cells characterized by the ability to renew themselves through mitotic cell division and differentiate into a diverse range of specialized cell types. Human stem cells are typically totipotential or pluripotential precursor cells capable of self renewal and generating a variety of mature human cell lineages. This ability serves as the basis for the cellular differentiation and specialization necessary for organ and tissue development. Recent evidence demonstrates that stem cells can be employed to repopulate many, if not all, tissues and restore physiologic and anatomic functionality. Accordingly, stem cells have the potential to be used in treating a wide variety of diseases and injuries, including nervous system trauma, malignancies, genetic diseases, hemoglobinopathies, and immunodeficiency. Many different types of mammalian stem cells have been characterized. Examples include embryonic stem cells, embryonic germ cells, adult stem cells, and other committed stem cells or progenitor cells are known. In addition, umbilical cord blood is a known alternative source of mesenchymal stem cells as well as hematopoietic stem cells and progenitor cells.
However, applications of these cells are often hampered by logistical issues. For example, stem cells (including cord blood cells), once collected, are routinely cryopreserved at storage facilities (such as cell banks) and, when needed, transported from the facilities to hospitals. This cryopreservation process, where cells or tissues are preserved by cooling to low sub-zero temperatures, typically 77 K or −196° C. (the boiling point of liquid nitrogen), entails certain risks. For example, cells being preserved can be damaged due to freezing during the approach to low temperatures or warming to room temperature. These risks are particularly serious for stem cells (including cord blood cells) as one of the most important aspects in stem cell transplantation is the number of viable stem cells and their developmental potentials at time of transplantation. Out of this concern, stem cells are routinely shipped cryopreserved over a time period as short as possible. Indeed, overnight shipments on dry ice or in a liquid nitrogen shipper are the industry standard and extra care must be taken to monitor the temperatures. Yet, this practice does not eliminate the risks. Also, it is extraordinarily costly and not practical for long-distance (e.g., trans-continental) transportation.
Thus, there is a strong need for more practical processes or methods of shipping stem cells. The present invention satisfies this and other needs.